Electronic apparatus, method for control rolling electronic apparatus, and control program

ABSTRACT

To reduce power consumed when the display magnification of an image is changed. A digital camera includes a display unit having a first display region in which a first image is displayed and a second display region in which a second image is displayed, an image capture unit having a first image capture region in which first image data indicating the first image is generated and a second image capture region in which second image data indicating the second image is generated, magnification change units that change the display magnifications of the first and second images displayed on the display unit, and an image capture control unit that when the magnification change units change the display magnifications, changes the charge accumulation conditions or reading conditions of the first and second image capture regions.

TECHNICAL FIELD

The present invention relates to an electronic apparatus, a method forcontrolling an electronic apparatus, and a control program.

BACKGROUND ART

Electronic apparatuses each including an image sensor in which aback-illuminated image-capture chip and a signal processing chip arestacked (hereafter referred to as a stacked image sensor) have beenproposed (for example, see Patent Literature 1). In a stacked imagesensor, a back-illuminated image capture chip and a signal processingchip are stacked so as to be connected via micro-bumps corresponding toblocks each including multiple pixels.

CITATION LIST Patent Literature

[Patent Literature 1] Japanese Unexamined Patent Application PublicationNo. 2006-49361

SUMMARY OF INVENTION Technical Problem

However, there have been proposed only a few electronic apparatusesincluding a stacked image sensor that captures images on amultiple-block basis. Accordingly, the usability of electronicapparatuses including a stacked image sensor has not been sufficientlyimproved.

An object of an aspect of the present invention is to reduce powerconsumed when the display magnification of an image is changed.

Solution to Problem

A first aspect of the present invention provides an electronic apparatusincluding a display unit having a first display region in which a firstimage is displayed and a second display region in which a second imageis displayed, an image capture unit having a first image capture regionin which first image data indicating the first image is generated and asecond image capture region in which second image data indicating thesecond image is generated, a magnification change unit configured tochange display magnifications of the first and second images displayedon the display unit, and an image capture control unit configured to,when the magnification change unit changes the display magnifications,changes charge accumulation conditions or reading conditions of thefirst and second image capture regions.

A second aspect of the present invention provides a method forcontrolling an electronic apparatus, the electronic apparatus includinga display unit having a first display region in which a first image isdisplayed and a second display region in which a second image isdisplayed and an image capture unit having a first image capture regionin which first image data indicating the first image is generated and asecond image capture region in which second image data indicating thesecond image is generated. The method includes changing displaymagnifications of the first and second images displayed on the displayunit; and when the display magnifications are changed, changing chargeaccumulation conditions or reading conditions of the first and secondimage capture regions.

A third aspect of the present invention provides a control program forcausing a control unit of an electronic apparatus to perform amagnification change process and an image capture control process. Theelectronic apparatus includes a display unit having a first displayregion in which a first image is displayed and a second display regionin which a second image is displayed and an image capture unit having afirst image capture region in which first image data indicating thefirst image is generated and a second image capture region in whichsecond image data indicating the second image is generated. Themagnification change process is a process of changing displaymagnifications of the first and second images displayed on the displayunit. The image capture control process is a process of, when thedisplay magnifications are changed in the magnification change process,changing charge accumulation conditions or reading conditions of thefirst and second image capture regions.

Advantageous Effects of the Invention

According to this configuration, it is possible to reduce power consumedwhen the display magnification of an image is changed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a schematic configuration of adigital camera, which is an electronic apparatus.

FIG. 2 is a sectional view of a stacked image sensor.

FIG. 3 is a diagram showing the pixel array of an image capture chip anda unit group.

FIG. 4 is a circuit diagram of a unit group of the image capture chip.

FIG. 5 is a block diagram showing the functional configuration of animage sensor.

FIG. 6 is a block diagram showing the configuration of the digitalcamera, which is an electronic apparatus.

FIG. 7 is a function block diagram of an image processing unit and asystem control unit shown in FIG. 6.

FIG. 8 is a diagram showing an example display when an optical zoom isperformed.

FIG. 9 is a diagram showing an example display when an electronic zoomis performed.

FIG. 10 is a flowchart showing an image capture process according to afirst embodiment.

FIG. 11 is a flowchart showing control corresponding to the optical zoomshown in FIG. 10.

FIG. 12 includes diagrams showing a central region and a peripheralregion in an image capture region.

FIG. 13 is a flowchart showing control corresponding to the electroniczoom shown in FIG. 10.

FIG. 14 is a diagram showing a region to be enlarged in the imagecapture region.

FIG. 15 is a flowchart showing an image capture process according to asecond embodiment.

FIG. 16 is a flowchart showing control corresponding to an optical zoomshown in FIG. 15.

FIG. 17 is a diagram showing a main subject region and a feature pointregion set in an image capture region when performing the optical zoom.

FIG. 18 is a flowchart showing control corresponding to an electroniczoom shown in FIG. 15.

FIG. 19 is a diagram showing a main subject region and a feature pointregion set in the image capture region when performing the electroniczoom.

FIG. 20 is a flowchart showing control corresponding to an electroniczoom according to a third embodiment.

FIG. 21 is a diagram showing an example display when the electronic zoomis performed in the third embodiment.

FIG. 22 is a diagram showing another example display when the electroniczoom is performed in the third embodiment.

FIG. 23 is a block diagram showing the configuration of an image capturedevice and an electronic apparatus according to a fourth embodiment.

DESCRIPTION OF EMBODIMENTS

Now, embodiments of the present invention will be described withreference to the drawings. However, the present invention is not limitedthereto. To clarify the embodiments, the drawings may be scaled asappropriate, for example, partially enlarged or highlighted. In theembodiments below, interchangeable-lens digital cameras will be used asexamples of electronic apparatuses.

First Embodiment

FIG. 1 is a cross-sectional view showing a schematic configuration of adigital camera, which is an example of an electronic apparatus. Adigital camera (electronic apparatus) 1 according to the presentembodiment includes a lens unit 10 serving as an interchangeable lensand a camera body 2. The lens unit 10 is inserted into the camera body 2through a mounting part 80. The lens unit 10 including various types ofimage capture optical systems can be inserted into the camera body 2through the mounting part 80. Hereafter, the image capture opticalsystems (a lens 11 a, a zoom lens 11 b, a focus lens 11 c) in the lensunit 10 will be collectively referred to as the “image capture opticalsystem 11.”

The lens unit 10 includes the lens 11 a, the zoom lens 11 b, the focuslens 11 c, a diaphragm 11 d, and a lens drive controller 15. The lensdrive controller 15 includes a central processing unit (CPU), a memory,and a drive control circuit. The lens drive controller 15 communicateswith a system control unit 70 in the camera body 2 through an electricalcontact 80A. Specifically, the lens drive controller 15 transmits lensinformation about properties of the lens 11 a (lens size, etc.) to thesystem control unit 70 and receives control information (the amount ofmovement of the zoom lens 11 b, the amount of movement of the focus lens11 c, the aperture value of the diaphragm 11 d, etc.) therefrom.

To control the focus of the image capture optical system 11, the lensdrive controller 15 causes the drive control circuit to control thedrive of the focus lens 11 c on the basis of control informationtransmitted by the system control unit 70. Also, to control zooming, thelens drive controller 15 causes the drive control circuit to control thedrive of the zoom lens 11 b on the basis of control informationtransmitted by the system control unit 70. The diaphragm 11 d forms anaperture which controls the amount of light and the amount of blur andwhose diameter is variable centered on the optical axis. To control theaperture diameter of the diaphragm 11 d, the lens drive controller 15causes the drive control circuit to control the drive of the diaphragm11 d on the basis of control information transmitted by the systemcontrol unit 70.

When the drive control circuit controls the drive of the zoom lens 11 b,the focal length is changed without changing the focal position and thusthe display magnification of an image displayed on a display unit 50 ischanged (increased or reduced). Changing the display magnification of animage by moving the zoom lens 11 b is called an “optical zoom.”

The camera body 2 includes an image capture unit 20 including a stackedimage sensor, an image processing unit 30, a display unit 50, a storageunit 60, and the system control unit 70. A light beam passed through thelens unit 10 forms a subject image on the light receiving surface of theimage sensor of the image capture unit 20. The image sensorphotoelectrically converts the subject image and transmits signals ofthe pixels thereof to the image processing unit 30. The image processingunit 30 performs various types of image processing on raw data composedof, the pixel signals to generate image data. The display unit 50displays the image data generated by the image processing unit 30. Thestorage unit 60 stores the image data generated by the image processingunit 30.

As used herein, the term “image data” refers to data forming an image(still image, moving image, live view image) captured by the imagecapture unit 20. The image data includes data which has yet to beprocessed by the image processing unit 30 (i.e., raw data) and datawhich has been processed thereby. The term “raw data” refers to imagedata which has yet to be processed by the image processing unit 30.Hereafter, the term “image data” may be referred to as “image signal.”

The term “live view images” refer to images displayed on the displayunit 50 on the basis of image data sequentially generated and outputtedby the image processing unit 30. The user uses live view images to checkimages of the subject being captured by the image capture unit 20. Liveview images are also called through images or preview images.

The system control unit 70 controls the entire processing and operationof the digital camera 1. The system control unit 70 includes a centralprocessing unit (CPU). Details of processing and operation performed bythe system control unit 70 will be described later (see FIGS. 6 and 7).Details of the elements in the camera body 2 will also be describedlater (see FIG. 6).

FIG. 2 is a sectional view of a stacked image sensor. This stacked imagesensor is the image sensor 100 disposed in the image capture unit 20shown in FIG. 1. The stacked image sensor 100 is disclosed in JapanesePatent Application No. 2012-139026 previously filed by the presentapplicant. The image sensor 100 includes an image-capture chip 113configured to out put a pixel signal corresponding to incident light, asignal processing chip 111 configured to process the pixel signal, and amemory chip 112 configured to store the pixel signal. The image-capturechip 113, signal processing chip 111, and memory chip 112 are stackedand electrically connected to one another via conductive bumps 109 suchas Cu.

As shown in FIG. 2, incident light enters the image sensor 100 in apositive z-axis direction mainly shown by an outline arrow. In thepresent embodiment, the incident light entry surface of theimage-capture chip 113 is referred to as a back surface. Further, asshown by coordinate axes, the direction which is perpendicular to thez-axis and oriented to the left side of the drawing is referred to as apositive x-axis direct ion, and the direction which is perpendicular tothe z- and x-axes and oriented to the viewer is referred to as apositive y-axis direction. In the following some drawings, coordinateaxes are shown using the coordinate axes of FIG. 2 as a reference sothat the orientations of such drawings are understood.

One example of the image-capture chip 113 is a back-illuminated MOSimage sensor. A PD layer 106 is disposed on the back surface of a wiringlayer 108. The PD layer 106 includes multiple photodiodes (PDs) 104disposed two-dimensionally and configured to accumulate chargecorresponding to incident light and transistors 105 disposed in a mannercorresponding to the PDs 104.

Color filters 102 are disposed over the incident light entry surface ofthe PD layer 106 with a passivation film 103 therebetween. The colorfilters 102 are each a filter which transmits a particular wavelengthrange of visible light. That is, the color filters 102 include multiplecolor filters which transmit different wavelength ranges and arearranged in a particular manner so as to correspond to the PDs 104. Thearrangement of the color filters 102 will be described later. A set of acolor filter 102, a PD 104, and a transistor 105 forms one pixel.

Microlenses 101 are disposed on the incident light entry sides of thecolor filters 102 in a manner corresponding to the pixels. Themicrolenses 101 condense incident light toward the corresponding PDs104.

The wiring layer 108 includes lines 107 configured to transmit pixelsignals from the PD layer 106 to the signal processing chip 111. Thelines 107 may be multilayered and may include passive and activeelements. Multiple bumps 109 are disposed on the front surface of thewiring layer 108 and aligned with multiple bumps 109 disposed on theopposite surface of the signal processing chip 111. The aligned bumps109 are bonded together and electrically connected together, forexample, by pressurizing the image-capture chip 113 and signalprocessing chip 111.

Similarly, multiple bumps 109 are disposed on the opposite surfaces ofthe signal processing chip 111 and memory chip 112 and aligned with eachother. The aligned bumps 109 are bonded together and electricallyconnected together, for example, by pressurizing the signal processingchip 111 and memory chip 112.

The methods for bonding the bumps 109 together include Cu bump bondingusing solid phase diffusion, as well as micro-bump bonding using soldermelting. For the bumps 109, it is only necessary to provide, forexample, one bump or so with respect to one unit group (to be discussedlater). Accordingly, the size of the bumps 109 may be larger than thepitch between the PDs 104. Further, bumps which are larger than thebumps 109 corresponding to a pixel region having the pixels arranged therein (a pixel region 113A shown in FIG. 3) may be additionally providedin peripheral regions other than the pixel region.

The signal processing chip 111 includes a through-silicon via (TSV) 110configured to connect together circuits disposed on the front and backsurfaces thereof. The TSV 110 is disposed in a peripheral region.Alternatively, the TSV 110 may be disposed in a peripheral region of theimage-capture chip 113 or in the memory chip 112.

FIG. 3 is a diagram showing the pixel array of the image-capture chipand a unit group. In FIG. 3, the image-capture chip 113 is observed fromthe back side. The pixel region (image capture region) 113A is thepixel-arranged region of the image-capture chip 113. In the pixel region113A, 20 million or more pixels are arranged in a matrix. In an exampleshown in FIG. 3, four adjacent pixels×four adjacent pixels, that is, 16pixels form one unit group 131. Grid lines in FIG. 3 show a concept thatadjacent pixels are grouped into unit groups 131. The number of pixelsforming the unit groups 131 is not limited to that described above andmay be on the order of 1000, for example, 32 pixels×64 pixels, or may be1000 or more or less than 1000.

As shown in a partial enlarged view of the pixel region 113A, one unitgroup 131 includes four so-called Bayer arrays which each includes fourpixels, that is, green pixels Gb, Gr, a blue pixel B, and a red pixel Rand which are arranged vertically and horizontally. The green pixels areeach a pixel having a green filter as a color filter 102 and receivelight in the green wavelength band of incident light. Similarly, theblue pixel is a pixel having a blue filter as a color filter 102 andreceives light in the blue wavelength band. The red pixel is a pixelhaving a red filter as a color filter 102 and receives light in the redwavelength band.

FIG. 4 is a circuit diagram of a unit group of the image-capture chip.In FIG. 4, a rectangle surrounded by a dotted line as a representativeshows the circuit of one pixel. At least part of each transistordescribed below corresponds to one transistor 105 in FIG. 2.

As described above, one unit group 131 includes 16 pixels. Sixteen PDs104 included in these pixels are connected to corresponding transfertransistors 302. The gates of the transfer transistors 302 are connectedto a TX line 307 through which a transfer pulse is supplied. In thepresent embodiment, the TX line 307 is shared by the 16 transfertransistors 302.

The drain of each transfer transistor 302 is connected to the source ofa corresponding reset transistor 303, and so-called floating diffusionFD (charge detection unit) therebetween is connected to the gate of acorresponding amplifier transistor 304. The drains of the resettransistors 303 are connected to a Vdd line 310 through which apower-supply voltage is supplied. The gates of the reset transistors 303are connected to a reset line 306 through which a reset pulse issupplied. In the present embodiment, the reset line 306 is shared by the16 reset transistors 303.

The drains of the amplifier transistors 304 are connected to the Vddline 310, through which a power-supply voltage is supplied. The sourcesof the amplifier transistors 304 are connected to the drains ofcorresponding select transistors 305. The gates of the selecttransistors 305 are connected to corresponding decoder lines 308 throughwhich a selection pulse is supplied. In the present embodiment, thedifferent decoder lines 308 are disposed with respect to the 16 selecttransistors 305. The sources of the select transistors 305 are connectedto a shared output line 309. A load current source 311 supplies acurrent to the output line 309. That is, the output line 309 withrespect to the select transistors 305 is formed by a source follower.The load current source 311 may be disposed in any of the image-capturechip 113 and signal processing chip 111.

Described below is the flow from when the accumulation of charge startsto when pixel signals are outputted after the accumulation ends. Resetpulses are applied to the reset transistors 303 through the reset line306. Simultaneously, transfer pulses are applied to the transfertransistors 302 through the TX line 307. Thus, the potentials of the PDs104 and floating diffusion FD are reset.

When the application of the transfer pulses is released, the PDs 104convert received incident light into charge and accumulate it.Subsequently, when transfer pulses are applied again with reset pulsesnot being applied, the charge accumulated in each PD 104 is transferredto the corresponding floating diffusion FD. Thus, the potential of thefloating diffusion FD is changed from the reset potential to the signalpotential after the charge accumulation. When selection pulses areapplied to the select transistors 305 through the decoder lines 308, thevariation in the signal potential of each floating diffusion FD istransmitted to the output line 309 through the corresponding amplifiertransistor 304 and select transistor 305. Based on such a circuitoperation, the unit pixels output, to the output line 309, pixel signalscorresponding to the reset potentials and pixel signals corresponding tothe signal potentials.

As shown in FIG. 4, in the present embodiment, the reset line 306 and TXline 307 are shared by the 16 pixels forming the unit group 131. Thatis, reset pulses and transfer pulses a re simultaneously applied to allthe 16 pixels. Accordingly, all the pixels forming the unit group 131start to accumulate charge at the same timing and end the chargeaccumulation at the same timing. Note that selection pulses aresequentially applied to the select transistors 305 and therefore pixelsignals corresponding to the accumulated charge are selectively outputted to the output line 309. Different reset lines 306, TX lines 307,and output lines 309 are disposed for the respective unit groups 131.

By constructing the circuit on the basis of unit groups 131 as describedabove, the charge accumulation time can be controlled for each unitgroup 131. In other words, it is possible to cause the unit groups 131to output pixel signals based on different charge accumulation times.More specifically, by causing another unit group 131 to accumulatecharge several times and to output pixel signals each time while oneunit group 131 is caused to accumulate charge once, it is possible tocause the unit groups 131 to output moving image frames at differ entframe rates.

FIG. 5 is a block diagram showing the functional configuration of theimage sensor. An analog multiplexer 411 sequent Tally selects 16 PDs 104forming one unit group 131 and causes each selected PD 104 to output apixel signal to an output line 309 disposed in a manner corresponding tothe unit group 131. The multiplexer 411 is formed along with the PDs 104in the image-capture chip 113.

The analog pixel signals outputted through the multiplexer 411 areamplified by an amplifier 412 which is formed in the signal processingchip 111. The pixel signals amplified by the amplifier 412 are subjectedto correlated double sampling CDS) and analog-to-digital (A/D)conversion by a signal processing circuit 413 formed in the signalprocessing chip 111 and configured to perform CDS and A/D conversion.Since the pixel signals are subjected to CDS by the signal processingcircuit 413, the noise in the pixel signals is reduced. TheA/D-converted pixel signals are passed to a demultiplexer 414 and thenstored in corresponding pixel memories 415. The demultiplexer 414 andpixel memories 415 are formed in the memory chip 112.

An arithmetic circuit 416 processes the pixel signals stored in thepixel memories 415 and passes the resulting signals to a subsequentimage processing unit. The arithmetic circuit 416 may be disposed in anyof the signal processing chip 111 and memory chip 112. While theelements connected to the single unit group 131 are shown in FIG. 5,these elements are disposed for each unit group 131 in practice andoperate in parallel. Note that the arithmetic circuit 416 need notnecessarily be disposed for each unit group 131. For example, a singlearithmetic circuit 416 may sequentially refer to and process the valuesin the pixel memories 415 corresponding to the respective unit groups131.

As described above, the output lines 309 are disposed in a mannercorresponding to the respective unit groups 131. In the image sensor100, the image-capture chip 113, signal processing chip 111, and memorychip 112 are stacked. Accordingly, by using, as the output lines 309,the bumps 109 electrically connecting between the chips, the lines canbe routed without enlarging the chips in the surface direction.

Next, blocks set in the pixel region 113A (see FIG. 3) of the imagesensor 100 will be described. In the present embodiment, the pixelregion 113A of the image sensor 100 is divided into multiple blocks.Each block includes at least one unit group 131. Pixels included in therespective blocks are controlled by different control parameters. Thatis, the control parameter varies between pixel signals acquired frompixels included in one block and pixel signals acquired from pixelsincluded in another block. Examples of a control parameter include thecharge accumulation time or frequency, the frame rate, the gain, thethinning-out rate (pixel thinning-out rates), the number of rows orcolumns whose pixel signals are summed up (pixel summation numbers), andthe digitized bit number. The control parameters may be parameters usedin image processing following the acquisition of image signals from thepixels.

As used herein, the charge accumulation time refers to the time fromwhen the PDs 104 start to accumulate charge to when they end theaccumulation. The charge accumulation time also refers to “exposuretime” or “shutter speed.” The charge accumulation frequency refers tothe frequency with which the PDs 104 accumulate charge per unit time.The frame rate refers to the number of frames processed (displayed orrecorded) per unit time in a moving image. The frame rate is expressedin frames per second (fps). As the frame rate is increased, a subject(i.e., subjects whose images are to be captured) moves more smoothly ina moving image.

The gain refers to the gain factor (amplification factor) of theamplifier 412. By changing the gain, the ISO sensitivity can be changed.The ISO sensitivity is a standard for photographic films developed bythe ISO and represents the level of the weakest light which aphotographic film can record. Typically, the sensitivity of imagesensors is represented by the ISO sensitivity. In this case, the abilityof the image sensor 100 to capture light is represented by the value ofthe ISO sensitivity. When the gain is increased, the ISO sensitivity isincreased as well. For example, when the gain is doubled, the electricalsignal (pixel signal) is doubled as well. Thus, appropriate brightnessis obtained even when the amount of incident light is halved. However,the increase in gain amplifies noise included in the electric signal,thereby increasing noise.

The thinning-out rate refers to the ratio of the number of pixels fromwhich pixel signals are not read to the total number of pixels in apredetermined region. For example, a thinning-out rate of apredetermined region of 0 means that pixel signals are read from allpixels in the predetermined region. A thinning-out rate of apredetermined region of 0.5 means that pixel signals are read from halfthe pixels in the predetermined region. Specifically, where a unit group131 is a Bayer array, one Bayer array unit from which pixel signals areread and one Bayer array unit from which pixel signals are not read arealternately set in the vertical direction, that is, two pixels (tworows) from which pixel signals are read and two pixels (two rows) fromwhich pixel signals are not read are alternately set in the verticaldirection. On the other hand, when the pixels from which pixel signalsare read are thinned out, the resolution of images is reduced. However,20 million or more pixels are arranged in the image sensor 100 andtherefore, even when the pixels are thinned out, for example, at athinning-out rate of 0.5, images can be displayed with 10 million ormore pixels. For this reason, the user (operator) seems not to worryabout such a resolution reduction.

The number of rows whose pixel signals are summed up refers to thenumber of vertically adjacent pixels whose pixel signals are summed up.The number of columns whose pixel signals are summed up refers to thenumber of horizontally adjacent pixels whose pixel signals are summedup. Such a summation process is performed, for example, in thearithmetic circuit 416. When the arithmetic circuit 416 sums up pixelsignals of a predetermined number of vertically or horizontally adjacentpixels, there is obtained an effect similar to that obtained by thinningout the pixels at a predetermined thinning-out rate and reading pixelsignals from the resulting pixels. In the summation process, an averagevalue may be calculated by dividing the sum of the pixel signals by therow number or column number obtained by the arithmetic circuit 416.

The digitized bit number refers to the number of bits of a digitalsignal converted from an analog signal by the signal processing circuit413. As the number of bits of a digital signal is increased, luminance,color change, or the like is re presented in more detail.

In the present embodiment, the term “charge accumulation conditions”refer to conditions on the accumulation of charge in the image sensor100. Specifically, the charge accumulation conditions refer to thecharge accumulation time or frequency, frame rate, and gain among thecontrol parameters. Since the frame rate can vary with the chargeaccumulation time or frequency, it is included in the chargeaccumulation conditions. Similarly, the correct amount of exposure canvary with the gain, and the charge accumulation time or frequency canvary with the correct amount of exposure. Accordingly, the gain isincluded in the charge accumulation conditions.

In the present embodiment, the term “reading conditions” refer toconditions on the reading of pixel signals by the image sensor 100.Specifically, the reading conditions refer to thinning-out rate and thenumber of rows or columns whose pixel signals are summed up (the numberof rows or columns whose pixel signals are summed up; hereafter referredto as “the pixel summation number” or “the summation number”) among thecontrol parameters. The number of pixel signals outputted from the imagesensor 100 varies with the thinning-out rate and summation number.

In the present embodiment, the term “image capture conditions” refer toconditions on image-capture of a subject. Specifically, the imagecapture conditions refer to control parameters including the chargeaccumulation conditions and reading conditions. The image captureconditions includes control parameters for controlling the image sensor100 (e.g., the charge accumulation time or frequency, frame rate, gain),as well as control parameters for controlling reading of signals fromthe image sensor 100 (e.g., thinning-out rate, the number of rows orcolumns whose pixel signals are summed up) and control parameters forprocessing signals from the image sensor 100 (e.g., digitized bitnumber, control parameters that the image processing unit 30 (to bediscussed later) uses to process images).

FIG. 6 is a block diagram showing the configuration of the digitalcamera (electronic apparatus) according to the first embodiment. Asshown in FIG. 6, the digital camera 1, which is an electronic apparatus,includes the camera body 2 and lens unit 10. As described above, thelens unit 10 is an interchangeable lens, which is detachable from thecamera body 2. Accordingly, the digital camera 1 need not include thelens unit 10. Note that the lens unit 10 may be integral with thedigital camera 1. The lens unit 10 connected to the camera body 2 guidesa light beam from the subject to the image capture unit 20.

As described above, the lens unit 10 includes the lens drive controller15 (see FIG. 1). The lens unit 10 also includes the multiple lensesforming the image capture optical system 11, that is, the lens 11 a,zoom lens 11 b, and focus lens 11 c. When the lens unit 10 is connectedto the camera body 2, the lens drive controller 15 transmits lensinformation stored in the memory to the system control unit of thecamera body 2. Also, when the lens unit 10 is connected to the camerabody 2, the lens drive controller 15 receives control information fromthe system control unit 70, and the lens drive controller 15 controlsthe drive of the zoom lens 11 b, focus lens 11 c, and diaphragm 11 d onthe basis of the control information.

As shown in FIG. 6, the camera body 2 includes the image capture unit20, the image processing unit 30, a work memory 40, the display unit 50,an operation unit 55, the storage unit 60, and the system control unit70.

The image capture unit 20 includes the image sensor 100 and a drive unit21. The drive unit 21 is a control circuit that controls the drive ofthe image sensor 100 in accordance with an instruction from the systemcontrol unit 70. Specifically, the drive unit 21 controls the chargeaccumulation time or frequency, which is a control parameter, bycontrolling the timing (or the cycle of the timing) when reset pulses ortransfer pulses are applied to the reset transistors 303 or transfertransistors 302, respectively. The drive unit 21 also controls the framerate by controlling the timing (or the cycle of timing) when resetpulses, transfer pulses, or selection pulses are applied to the resettransistors 303, transfer transistor 302, or select transistors 305,respectively. The drive unit 21 also controls the thinning-out rate bysetting pixels to which reset pulses, transfer pulses, or selectionpulses are applied.

The drive unit 21 also controls the ISO sensitivity of the image sensor100 by controlling the gain (also called the gain factor oramplification factor) of the amplifier 412. The drive unit 21 also setsthe number of rows or columns whose pixel signals are summed up bytransmitting an instruction to the arithmetic circuit 416. The driveunit 21 also sets the digitized bit number by transmitting aninstruction to the signal processing circuit 413. The drive unit 21 alsosets a region(s) in the pixel region (image capture region) 113A of theimage sensor 100 in units of blocks. As seen above, the drive unit 21serves as an image sensor control unit that causes the image sensor 100to capture images on the image capture conditions which vary among thegroups of multiple blocks and then to output pixel signals. The systemcontrol unit 70 transmits an instruction about the positions, shapes,ranges, or the like of the blocks to the drive unit 21.

The image sensor 100 passes the pixel signals from the image sensor 100to the image processing unit 30. The image processing unit 30 performsvarious types of image processing on raw data composed of the pixelsignals using the work memory 40 as work space to generate image data ina predetermined file format (e.g., JPEG). For example, the imageprocessing unit 30 performs image processing as follows: it performscolor signal processing (color tone correction) on the signals obtainedfrom the Bayer array to generate RGB image signals, then performs imageprocessing such as white balance adjustment, sharpness adjustment, gammacorrection, gradation adjustment, or the like on the RGB image signals,and optionally compresses the resulting signals in a predeterminedcompression format (JPEG format, MPEG format, or the like). The imageprocessing unit 30 then outputs the resulting image data to the storageunit 60. The image processing unit 30 also outputs the image data to thedisplay unit 50.

In the present embodiment, in addition to performing the aboveprocessing, the image processing unit 30 cuts out (trims) image data ofa predetermined region indicated by the system control unit 70. Thesystem control unit 70 outputs the image data of the predeterminedregion cut out by the image processing unit 30 to the display unit 50 sothat an image based on the image data of the predetermined region isdisplayed on the display panel (display surface) 51 of the display unit50 in an enlarged manner. Cutting out part of an image and displayingthe image part in an enlarged manner is called “electronic zoom” or“digital zoom.”

In the present embodiment, in addition to the above processing, theimage processing unit 30 detects a main subject from the image data. Asused herein, the term “main subject” refers to a subject which is noted,or believed to be noted, by the user (operator), of subjects whoseimages are captured. The number of main subjects in the image data isnot limited to one, and multiple main subjects may exist therein. In thepresent embodiment, in addition to the above processing, the imageprocessing unit 30 detects feature points of the main subject from theimage data. As used herein, the term “feature points” refer to featuringportions of the main subject. The number of feature points in the imagedata is not limited to one, and multiple feature points may existtherein.

Parameters that the image processing unit 30 refers to when performingimage processing are also included in the control parameters (imagecapture conditions). For example, parameters, such as color signalprocessing (color tone correction), white balance adjustment, gradationadjustment, and compressibility are included in the control parameters.The signals read from the image sensor 100 vary with the chargeaccumulation time or the like, and the parameters that the imageprocessing unit 30 refers to when performing image processing vary withthe variations in the signals. The image processing unit 30 setsdifferent control parameters for the respective blocks and performsimage processing, such as color signal processing, on the basis of thesecontrol parameters.

The work memory 40 temporarily stores the image data or the like whenthe image processing unit 30 performs image processing. The display unit50 displays the images (still images, moving images, live view images)captured by the image capture unit 20 or various types of information.The display unit 50 includes the display panel (display surface) 51,such as a liquid crystal display panel. A touchscreen 51 is formed onthe display panel 51 of the display unit 50. When the user touches thetouchscreen 51 to perform an operation, such as selection of a menu, thetouchscreen 52 outputs a signal indicating the touched position to thesystem control unit 70.

The operation unit 55 includes operation switches operated by the user,such as a release switch (a switch pressed to capture still images), amoving image switch (a switch pressed to capture moving images), anoptical zoom switch (a switch pressed to perform the optical zoom), andan electronic zoom switch (a switch pressed to perform the electroniczoom). The operation unit 55 outputs a signal corresponding to anoperation performed by the user to the system control unit 70. Thestorage unit 60 has a card slot into which a storage medium, such as amemory card, can be inserted. The storage unit 60 stores the image datagenerated by the image processing unit 30 or various types of data in astorage medium inserted in the card slot. The storage unit 60 alsoincludes an internal memory. The storage unit 60 may store the imagedata generated by the image processing unit 30 or various types of datain the internal memory.

The system control unit 70 controls the entire processing and operationof the digital camera 1. As described above, the system control unit 70includes a central processing unit (CPU). In the present embodiment, thesystem control unit 70 divides the image capture surface (pixel region113A) of the image sensor 100 (image capture chip 113) into multipleblocks and causes the drive unit 21 to capture images in the blocks withdifferent charge accumulation times (or charge accumulationfrequencies), different frame rates, and/or different gains. For thisreason, the system control unit 70 transmits the positions, shapes, andranges of the blocks and the charge accumulation conditions for theblocks to the drive unit 21.

The system control unit 70 also causes the image sensor 100 to captureimages in the blocks at different thinning-out rates, the differentnumbers of rows or columns whose pixel signals are summed up, and/ordifferent digitized bit numbers. For this reason, the system controlunit 70 transmits, to the drive unit 21, the image capture conditions(thinning-out rates, the numbers of rows or columns whose pixel signalsare summed up, and digitized bit numbers) for the blocks. The imageprocessing unit 30 performs image processing on the pixel signals onimage capture conditions (control parameters, such as color signalprocessing, white balance adjustment, gradation adjustment, andcompressibility) which vary among the blocks. For this reason, the imageprocessing unit 70 transmits, to the image processing unit 30, the imagecapture conditions (control parameters, such as color signal processing,white balance adjustment, gradation adjustment, and compressibility) forthe blocks.

The system control unit 70 also stores the image data generated by theimage processing unit 30 in the storage unit 60. The system control unit70 also outputs the image data generated by the image processing unit 30to the display unit 50 so that images are displayed on the display unit50. The system control unit 70 also reads image data stored in thestorage unit 60 and outputs it to the display unit 50 so that images aredisplayed on the display unit 50. Images displayed on the display unit50 include still images, moving images, and live view images.

Also, in response to the user operating the optical zoom switch, thesystem control unit 70 outputs, to the lens drive controller 15, acontrol signal instructing the lens drive controller 15 to move the zoomlens 11 b. The lens drive controller 15 drives the zoom lens 11 b bycontrolling the drive control circuit on the basis of the controlinformation outputted from the system control unit 70. Thus, the displaymagnification of images displayed on the display panel 51 is changed.Also, in response to the user operating the electronic zoom switch orthe like, the system control unit 70 outputs, to the image processingunit 30, an instruction signal indicating a region whose image is to becut out. Thus, an image based on the image data of the region cut out bythe image processing unit 30 is displayed on the display panel 51 of thedisplay unit 50 in a manner enlarged at a predetermined displaymagnification. The system control unit 70 also outputs controlinformation to the lens drive controller 15 so that the lens drivecontroller 15 controls the drive of the focus lens 11 c and diaphragm 11d.

FIG. 7 is a function block diagram of the image processing unit andsystem control unit shown in FIG. 6. As shown in FIG. 7, the imageprocessing unit 30 includes an image generation unit 31, a subjectdetection unit (first detection unit) 32, and a feature point detectionunit (second detection unit) 33. The image generation unit 31 generatesimage data by performing various types of image processing on raw dataoutputted from the image capture unit 20 and composed of pixel signals.The subject detection unit 32 detects a main subject (e.g., a humanface) from the image data generated by the image generation unit 31. Forexample, the subject detection unit 32 detects a main subject using aknown face detection function as described in Japanese Unexamined PatentApplication Publication No. 2010-16621 (US 2010/0002940). The featurepoint detection unit 33 detects feature points (e.g., human eyes) of themain subject from the image data generated by the image generation unit31. For example, the feature point detection unit 33 detects featurepoints using a known feature point detection function as described inJapanese Unexamined Patent Application Publication No. 2010-16621 (US2010/0002940).

The system control unit 70 includes a first magnification change unit(magnification change unit) 71, a second magnification change unit(magnification change unit) 2, an image capture control unit 73, and adisplay control unit 74. The first magnification change unit 71 is aprocessing unit that performs the optical zoom in response to the useroperating the optical zoom switch. The second magnification change unit72 is a processing unit that performs the electronic zoom in response tothe user operating the electronic zoom switch or the like.

The image capture control unit 73 sets multiple regions in the pixelregion (image capture region) 113A of the image sensor 100 in units ofblocks. The image capture control unit 73 also sets image captureconditions (including charge accumulation conditions and readingconditions) for the multiple regions. Also, in response to the useroperating the release switch or moving image switch, the image capturecontrol unit 73 causes the drive unit 21 to control the drive of theimage sensor 100. Even when live view images are being captured (thatis, even after imaging is started following power-on), the image capturecontrol unit 73 causes the drive unit 21 to control the drive of theimage sensor 100. The display control unit 74 outputs the image datagenerated by the image generation unit 31 to the display unit 50 so thatimages (still images, moving images, or live view images) are displayedon the display panel 51.

Next, the optical zoom performed by the first magnification change unit71 will be described. FIG. 8 includes diagrams showing example displayswhen the optical zoom is performed. As shown in FIGS. 8(A) and 8(B), thetouchscreen 52 is formed on the display panel 51 of the display unit 50.Also, as shown in FIGS. 8(A) and 8(B), the optical axis (optical center)O of the image capture optical system 11 is located in the center of thedisplay panel 51. In the example display shown in FIG. 8(A), a humanimage C1 is displayed approximately in the center of the display panel51. The user can enlarge the human image C1 by operating the opticalzoom switch in a particular direction; the user can shrink the humanimage C1 by operating the optical zoom switch in a direction reverse tothe particular direction.

When the first magnification change unit 71 receives a signal indicatingthat the user has operated the optical zoom switch in the particulardirection, it outputs, to the lens drive controller 15, a control signalinstructing the lens drive controller 15 to move the zoom lens 11 b in adirection [a direction in which the human image C1 is enlarged in FIG.8(A)] corresponding to the particular direction. The lens drivecontroller 15 moves the zoom lens 11 b in the direction corresponding tothe particular direction on the basis of the control signal transmittedfrom the first magnification change unit 71. By moving the zoom lens 11b, the human subject image is enlarged centered on the optical axis onthe image capture surface of the image sensor 100. In the exampledisplay shown in FIG. 8(B), the human image C1 enlarged in response tothe operation of the optical zoom switch by the user is displayed on thedisplay panel 51.

Next, the electronic zoom performed by the second magnification changeunit 72 will be described. FIG. 9 includes diagrams showing exampledisplays when the electronic zoom is performed. Also in FIGS. 9(A) and9(B), the touchscreen 52 is formed on the display panel 51 of thedisplay unit 50. As shown in FIG. 9(A), the optical axis (opticalcenter) O of the image capture optical system 11 is located in thecenter of the display panel 51. In the example display shown in FIG.9(A), a human image C2 is displayed on a lower-left part of the displaypanel 51. For example, the user selects a region 510 to be displayed inan enlarged manner by the electronic zoom, by sliding a finger on thetouchscreen 52. In the example shown in FIG. 9(A), the region 510 to bedisplayed in an enlarged manner by the electronic zoom is a lower-leftregion of the display panel 51. Hereafter, the region to be displayed inan enlarged manner by the electronic zoom will be referred to as the“region to be enlarged.” The user can enlarge the region 510 to beenlarged by operating the electronic zoom switch.

The second magnification change unit 72 receives a signal indicating theregion 510 to be enlarged selected in response to the operation of thetouchscreen 52 by the user. The image capture control unit 73 receives asignal indicating that the user has operated the electronic zoom switchand outputs, to the image processing unit 30, a signal instructing theimage processing unit 30 to cut out (trim) the region 510 to beenlarged. The image generation unit 31 cuts out the image data of theregion 510 to be enlarged indicated by the second magnification changeunit 72. The image generation unit 31 then outputs the cut-out imagedata of the region 510 to be enlarged, to the display unit 50. As shownin FIG. 9(B), an image (human image C2) based on the image data of theregion 510 to be enlarged is displayed over the entire surface of thedisplay panel 51 of the display unit 50 in an enlarged manner. While, inthe example shown in FIG. 9(A), the user selects the lower-left regionof the display panel 51 as the region 510 to be enlarged, the user mayselect any region of the display panel 51.

Next, an image capture operation according to the first embodiment willbe described. FIG. 10 is a flowchart showing an image capture process(main process) according to the first embodiment. The process shown inFIG. 10 is performed when the user operates the operation unit 55 tostart to capture live view images after powering on the digital camera 1or when the user operates the operation unit (moving image switch) tostart to capture moving images after powering on the digital camera 1.That is, the process shown in FIG. 10 is performed to capture live viewimages or moving images.

In the process shown in FIG. 10, first, the image capture control unit73 starts image capture (step S1). Specifically, the image capturecontrol unit 73 outputs an instruction signal to the drive unit 21 sothat the drive unit 21 controls the drive of the image sensor 100 onpredetermined image capture conditions (including the chargeaccumulation conditions and reading conditions). The system control unit70 then determines whether the user has operated the optical zoom switch(step S2). If the system control unit 70 determines that the user hasoperated the optical zoom switch, the first magnification change unit 71and image capture control unit 73 perform control corresponding to theoptical zoom (step S3).

FIG. 11 is a flowchart showing control corresponding to the optical zoomshown in FIG. 10 (step S3). FIG. 12 includes diagrams showing thecentral region and peripheral region in the image capture region. In theprocess shown in FIG. 11, the first magnification change unit 71performs the optical zoom on the basis of the operation of the opticalzoom switch by the user (step S10). Specifically, the firstmagnification change unit 71 outputs, to the lens drive controller 15, acontrol signal corresponding to the operation amount of the optical zoomswitch. Then, the image capture control unit 73 sets, in the center ofthe display panel 51, a region 200 [see FIG. 12(A)] including the center(optical axis) O of a magnification change (increase or reduction) madeusing the optical zoom in the pixel region (image capture region) 113A(step S11). Hereafter, the region including the center O of amagnification change made using the optical zoom will be referred to asthe “central region.” In the example shown in FIG. 12(A), the centralregion 200 is a circular region centered on the optical axis O. Also,the region other than the central region 200 in the pixel region 113A,as shown in FIG. 12(A), will be referred to as the “peripheral region210.”

Then, the image capture control unit 73 controls (changes) the size ofthe central region 200 in accordance with the speed of the magnificationchange made using the optical zoom (step S12). As used herein, the term“the speed of the magnification change” refers to the speed at which themagnification of an image is changed (increased or reduced) using theoptical zoom. The first magnification change unit 71 detects theoperation amount of the optical zoom switch per unit time on the basisof a signal from the optical zoom switch. The first magnification changeunit 71 then determines the speed of the magnification change on thebasis of the operation amount of the optical zoom switch. The operationamount of the optical zoom switch corresponds to the amount of movement(the amount of drive) of the zoom lens 11 b. The image capture controlunit 73 then outputs, to the drive unit 21, an instruction signalindicating the central region 200 corresponding to the speed of themagnification change.

The image capture control unit 73 then outputs an instruction signal tothe drive unit 21 so that the image sensor 100 reads pixel signals inthe regions (central region 200, peripheral region 210) of the pixelregion 113A at different frame rates (step S13).

Typically, when the user is enlarging or shrinking an image (subjectimage) displayed on the display panel 51 by operating the optical zoomswitch, the image radially flows in the peripheral region of the displaypanel 51 faster than in the central region thereof. When the image isflowing in the peripheral region fast, the user has difficulty inrecognizing the image in the peripheral region and is less likely tocarefully look at the image in the peripheral region. In contrast, whenthe user is enlarging or shrinking the image using the optical zoom, theuser is paying attention to the image in the central region of thedisplay panel 51. Further, the image flows faster as the speed of themagnification change is increased. Accordingly, the user pays attentionto the image in a narrower central region.

For this reason, in step S12, the image capture control unit 73 controlsthe size of the central region 200, which the user is believed to bepaying attention to, in accordance with the speed of the magnificationchange made using the optical zoom. For example, the image capturecontrol unit 73 narrows the central region 200 as the speed of themagnification change is increased; it widens the central region 200 asthe speed of the magnification change is reduced. The image capturecontrol unit 73 outputs an instruction signal indicating the centralregion 200 corresponding to the speed of the magnification change.

In step S13, the image capture control unit 73 causes the drive unit 21to read pixel signals at a high frame rate in the central region 200,which the user is paying attention to, as well as to read pixel signalsat a low frame rate in the peripheral region 210, which the user is notpaying attention to. For example, when capturing live view images, theimage capture control unit 73 outputs, to the drive unit 21, aninstruction signal indicating 60 fps as the frame rate of the centralregion 200 and an instruction signal indicating 30 fps as the frame rateof the peripheral region 210. On the basis of the instruction signalsfrom the image capture control unit 73, the drive unit 21 reads pixelsignals in the central region 200 at 60 fps, as well as reads pixelsignals in the peripheral region 210 at 30 fps. Thus, live view imagesdisplayed on the display panel 51 move more smoothly in the central partthereof (the part corresponding to the central region 200) than in theperipheral region thereof (the part corresponding to the peripheralregion 210).

In step S13, the image capture control unit 73 may cause the drive unit21 to read pixel signals in the regions (central region 200, peripheralregion 210) at different thinning-out rates rather than at differentframe rates. For example, when capturing live view images, the imagecapture control unit 73 outputs, to the drive unit 21, an instructionsignal indicating 0.5 as the thinning-out rate of the central region 200and an instruction signal indicating 0.8 as the thinning-out rate of theperipheral region 210. The drive unit 21 reads pixel signals in thecentral region 200 at a thinning-out rate of 0.5, as well as reads pixelsignals in the peripheral region 210 at a thinning-out rate of 0.8.Thus, live view images are displayed in the central region of thedisplay panel 51 with higher resolution than in the peripheral regionthereof.

In step S13, the image capture control unit 73 may also cause the driveunit 21 to sum up pixel signals in the regions (central region 200,peripheral region 210) with different summation numbers (summation rownumbers or summation column numbers) rather than to read pixel signalsin the regions at different frame rates. For example, when capturinglive view images, the image capture control unit 73 outputs, to thedrive unit 21, an instruction signal indicating “2” as the summationnumber of the central region 200 and an instruction signal indicating“5” as the summation number of the peripheral region 210. The drive unit21 causes the arithmetic circuit 41 to sum up pixel signals using thesummation numbers indicated by the instruction signals from the imagecapture control unit 73. The arithmetic circuit 41 sums up the signalsof two rows or two columns of pixels stored in the pixel memory 415corresponding to the central region 200, as well as sums up the pixelsignals of five rows or five columns of pixels stored in the pixelmemory 415 corresponding to the peripheral region 210. Thus, live viewimage are displayed in the central region of the display panel 51 withhigher resolution than in the peripheral region thereof.

In step S13, the image capture control unit 73 may also cause the driveunit 21 to read pixel signals in the regions (central region 200,peripheral region 210) at different frame rates, as well as at differentthinning-out rates. In step S13, the image capture control unit 73 mayalso cause the drive unit 21 to read pixel signals in the regions(central region 200, peripheral region 210) at different frame rates, aswell as to sum up pixel signals in the regions with different summationnumbers.

While, in FIG. 12(A), the image capture control unit sets the singlecentral region 200 in the pixel region 113A, other configurations may beemployed. For example, as shown in FIG. 12(B), the image capture controlunit 73 may set two central regions, 201 and 202, in the pixel region113A. More specifically, the image capture control unit 73 may set theannular central region 202 around the circular central region 201.

Even in this case, the image capture control unit 73, in step S12,controls (changes) the sizes of the two central regions, 201 and 202, inaccordance with the speed of the magnification change made using theoptical zoom. Note that the image capture control unit 73 may controlthe size of only one of the central regions 201 and 202.

As described above, in step S13, the image capture control unit 73causes the drive unit 21 to read pixel signals in the regions (centralregions 201 and 202, peripheral region 210) of the pixel region 113A atdifferent frame rates. For example, the image capture control unit 73causes the drive unit 21 to read pixel signals in the central region201, which the user is paying highest attention to, at the highest framerate (e.g., 60 fps). The image capture control unit 73 also causes thedrive unit 21 to read pixel signals in the central region 202 at a lowerframe rate (e.g., 30 fps) than that of the central region 202. The imagecapture control unit 73 also causes the drive unit 21 to read pixelsignals in the peripheral region 210, which the user is not payingattention to, at a low frame rate (e.g., 15 fps). As described above,the image capture control unit may set different thinning-out rates ordifferent summation numbers (summation row numbers or summation columnnumbers) for the regions rather than, or in addition to, settingdifferent frame rates for the regions. The image capture control unit 73may set three or more central regions in the pixel region 113A.

Referring back to FIG. 10, if the system control unit 70 determines thatthe user has not operated the optical zoom switch (NO in step S2), itdetermines whether the user has operated the electronic zoom switch(step S4). If the system control unit 70 determines that the user hasoperated the electronic zoom switch, the second magnification changeunit and image capture control unit 73 perform control corresponding tothe electronic zoom (step S5).

FIG. 13 is a flowchart showing control corresponding to the electroniczoom shown in FIG. 10 (step S5). FIG. 14 is a diagram showing a regionto be enlarged in the image capture region. In the process shown in FIG.13, the second magnification change unit 72 sets, in the pixel region(image capture region) 113A, a region 220 to be enlarged (see FIG. 14)selected in response to the operation of the touchscreen by the user(step S21). At this time, the second magnification change unit 72outputs, to the image processing unit 30, a signal instructing the imageprocessing unit 30 to cut out the region 220 to be enlarged. However, ifthe region 220 to be enlarged and the entire region of the display panel51 have different aspect ratios, the image would be deformed afterenlarged by the electronic zoom. For this reason, the secondmagnification change unit 72 sets the region 220 to be enlarged in sucha manner that the region 220 to be enlarged has the same aspect ratio asthat of the display panel 51.

Then, the image capture control unit 73 causes the drive unit 21 to readpixel signals in the region 220 to be enlarged set by the secondmagnification change unit 72 in step S21 at a thinning-out ratecorresponding to the enlargement ratio of the electronic zoom (stepS22). As used herein, the term “enlargement ratio” refers to the ratiobetween the area of the region to be enlarged and the area of the entirescreen of the display panel 51. The “thinning-out rate corresponding tothe enlargement ratio” is, for example, a thinning-out rate such thatthe resolution of the image enlarged by the electronic zoom becomesidentical or similar to that of the yet-to-be-enlarged image.

Typically, the user does not need live view images or moving images tobe captured with high resolution. Accordingly, while live view images ormoving images are captured, pixel signals are read at a predeterminedthinning-out rate. For example, while live view images are captured,pixel signals are read at a thinning-out rate of 0.75. That is, pixelsignals are read from ¼ of all the pixels. On the other hand, whenperforming the electronic zoom, part of the image is cut out anddisplayed in an enlarged manner on the display unit 50. The enlargementof the image part using the electronic zoom reduces the resolutionthereof (i.e., pixel density) and thus image quality. Depending on theenlargement ratio of the electronic zoom, image quality may be reducedremarkably. For this reason, in step S22, the image capture control unit73 causes the drive unit 21 to read pixel signals at a thinning-out ratecorresponding to the enlargement ratio of the electronic zoom.

For example, assume that the image is enlarged by a factor of 2 usingthe electronic zoom. Also assume that the thinning-out rate beforeperforming the electronic zoom is 0.75 and the thinning-out rate afterperforming the electronic zoom is 0.5. That is, pixel signals are readfrom ¼ the pixels before performing the electronic zoom; pixel signalsare read from ½ the pixels after performing the electronic zoom. In thiscase, the resolution of the image does not vary between before and afterenlarging the image using the electronic zoom. Thus, a reduction in theresolution of the image after performing the electronic zoom isprevented.

Specifically, in step S22, the image capture control unit 73 calculatesan enlargement ratio on the basis of the ratio between the area of theregion 220 to be enlarged selected by the user and the area of theentire screen of the display panel 51. The image capture control unit 73then calculates a thinning-out rate after performing the electronic zoomon the basis of the calculated enlargement ratio and the thinning-outrate before performing the electronic zoom. The image capture controlunit 73 then outputs, to the drive unit 21, an instruction signalindicating the thinning-out rate after performing the electronic zoom.The drive unit 21 reads pixel signals from the region 220 to be enlargedat the thinning-out rate indicated by the image capture control unit 73.

Then, the image capture control unit 73 makes a setting such that pixelsignals are not read from the region other than the region 220 to beenlarged in the pixel region 113A (step S23). This is because in thepresent embodiment, the image of the region other than the region 220 tobe enlarged is not displayed on the display panel 51 after performingthe electronic zoom and therefore there is no need to read pixel signalsfrom that region.

In step S22, the image capture control unit 73 may cause the drive unit21 to sum up pixel signals with a summation number (summation row numberor summation column number) corresponding to the enlargement ratiorather than to read pixel signals at the thinning-out rate correspondingto the enlargement ratio. For example, assuming that the summationnumber before enlarging the image using the electronic zoom are “4” andthe enlargement ratio is twice, the image capture control unit 73outputs, to the drive unit 21, an instruction signal indicating “2” asthe summation number after enlarging the image using the electroniczoom. Even in this configuration, it is possible to prevent theresolution of the image from varying between before and after enlargingthe image using the electronic zoom.

Referring back to FIG. 10, if the system control unit 70 determines thatthe user has not operated the electronic zoom switch (NO in step S4),the image capture control unit 73 performs normal reading control (stepS6). Specifically, the image capture control unit 73 outputs, to thedrive unit 21, an instruction signal indicating normal image captureconditions (e.g., image capture conditions such that correct exposure ismade) to capture live view images or moving images. The drive unit 21causes the image capture unit 20 to capture images in the entire pixelregion 113A on the normal image capture conditions.

The image capture unit 20 outputs the pixel signals read in steps S3,S5, and S6 to the image processing unit 30. The image processing unit 31performs various types of image processing on pixel data composed of thepixel signals to generate image data in a predetermined file format. Ifthe user has operated the electronic zoom switch, the image generationunit 31 cuts out the image data of the region 220 to be enlargedindicated by the second magnification change unit 72.

Then, the display control unit 74 outputs the image data generated bythe image generation unit 31 to the display unit 50 so that images(moving images, live view images) are displayed on the display panel 51(step S7). If the user has operated the electronic zoom switch, thedisplay control unit 74 displays the image of the region 220 to beenlarged cut out by the image generation unit 31 over the entire surfaceof the display panel 51 (see FIG. 9).

While moving images are captured, the system control unit 70 stores theimage data generated by the image generation unit 31 in the storage unit60 (step S8). Subsequently, the system control unit 70 determineswhether the image capture should be ended (step S9). If the useroperates the operation unit 55 to end the capture of live view images orif the user operates the operation unit 55 (moving image switch) to endthe capture of moving images, the system control unit 70 determines thatthe image capture should be ended. Otherwise, the system control unit 70repeats the process shown in FIG. 10 (steps S1 to S9) at predeterminedintervals until it determines that the image capture should be ended.

As described above, the digital camera 1 according to the firstembodiment includes the display unit 50, which has the first displayregion in which a first image is displayed and the second display regionin which a second image is displayed, the image capture unit 20, whichhas the first image capture region in which first image data indicatingthe first image is generated and the second image capture region inwhich second image data indicating the second image is generated, themagnification change units 71 and 72, which change the displaymagnifications of the first image and second image displayed on thedisplay unit 50, and the image capture control unit 73, which when themagnification change units 71 and 72 change the display magnifications,changes the charge accumulation conditions or reading conditions of thefirst and second image capture regions.

The “first display region” when performing the optical zoom is, forexample, a region on the display panel 51 corresponding to the centralregion 200 (or central regions 201, 202) on the image sensor 100; thatwhen performing the electronic zoom is, for example, a region on thedisplay panel 51 corresponding to the region 220 to be enlarged on theimage sensor 100. The “second display region” when performing theoptical zoom is, for example, a region on the display panel 51corresponding to the peripheral region 210 on the image sensor 100; thatwhen performing the electronic zoom is, for example, a region on thedisplay panel 51 corresponding to the region other than the region 220to be enlarged on the image sensor 100. The “first image capture region”when performing the optical zoom is, for example, the central region 200(or central regions 201, 202) on the image sensor 100; that whenperforming the electronic zoom is, for example, the region 220 to beenlarged on the image sensor 100. The “second image capture region” whenperforming the optical zoom is, for example, the peripheral region 210on the image sensor 100; that when performing the electronic zoom is,for example, the region other than the region 220 to be enlarged on theimage sensor 100.

According to this configuration, it is possible to reduce power consumedwhen the display magnification of an image is changed using the opticalzoom or electronic zoom. Specifically, when the optical zoom isperformed, the image capture control unit 73 reads signals in the secondimage capture region (peripheral region 210) at a lower frame rate thanthat of the first image capture region (central region 200). Thus, powerconsumption can be reduced compared to that when reading signals in thepixel region 113A at a uniform high frame rate. Also, when theelectronic zoom is performed, the image capture control unit 73 does notread signals from the second image capture region (the region other thanthe region 220 to be enlarged). Thus, power consumption can be reduced.

Cases in which the second magnification change unit 72 “changes thedisplay magnification of the second image” include a case in which thesecond image is not displayed. Cases in which the image capture controlunit 73 “changes the charge accumulation conditions or readingconditions of the first and second image capture regions” include a casein which signals are read in the first image capture region onpredetermined charge accumulation conditions or reading conditions andin which signals are not read in the second image capture region.

In the first embodiment, the image capture control unit 73 changes atleast one of the frame rates, pixel thinning-out rates, and pixelsummation numbers serving as charge accumulation conditions or readingconditions. According to this configuration, when the image capturecontrol unit 73 changes the frame rates of the first and second imagecapture regions, the first image and second image can move withdifferent degrees of smoothness. Further, when the image capture controlunit 73 changes the pixel thinning-out rates or pixel summation numbersof the first and second image capture regions, a difference can be madebetween the resolutions of the first and second images.

In the first embodiment, the image capture control unit 73 reduces theframe rate of the second image capture region, increases the pixelthinning-out rate thereof, and/or increases the pixel summation numberthereof compared to those of the first image capture region. Accordingto this configuration, when the image capture control unit 73 changesthe frame rates of the first and second image capture regions, the firstimage can move more smoothly than the second image on the display unit50. If the image capture control unit 73 changes the pixel thinning-outrates or pixel summation numbers of the first and second image captureregions, the resolution of the first image can be increased compared tothat of the second image.

The digital camera 1 according to the first embodiment includes thedifferent types of multiple magnification change units, 71 and 72, andthe image capture control unit 73 causes the drive unit 21 to captureimages on different charge accumulation conditions or reading conditionsin accordance with the magnification change units 71 and 72. Accordingto this configuration, the image capture control unit 73 can cause thedrive unit 21 to capture images on charge accumulation conditions orreading conditions in each of regions suitable for the optical zoom, aswell as can cause the drive unit 21 to capture images on chargeaccumulation conditions or reading conditions in each of regionssuitable for the electronic zoom.

In the first embodiment, the image capture control unit 73 has theoptical zoom which changes the display magnification of an image bymoving the image capture optical system 11. According to thisconfiguration, it is possible to make a difference between the chargeaccumulation conditions or reading conditions of the first and secondimage capture regions in accordance with a change in the displaymagnification of the image made using the optical zoom. In the firstembodiment, the first image capture region is a region including theoptical axis of the image capture optical system. According to thisconfiguration, it is possible to obtain a smoothly moving image orhigh-resolution image in the first image capture region including theoptical axis.

In the first embodiment, the magnification change unit 73 has theelectronic zoom which cuts out and enlarges part of a captured image.According to this configuration, it is possible to make a differencebetween the charge accumulation conditions or reading conditions of thefirst and second image capture regions in accordance with a change inthe display magnification of the image made using the electronic zoom.In the first embodiment, when the magnification change unit 72 changesthe display magnification of the first image using the electronic zoom,the image capture control unit 73 performs control such that images arenot captured in the second image capture region. According to thisconfiguration, power consumption can be reliably reduced.

In the first embodiment, in response to the first magnification changeunit 71 changing the display magnification, the image capture controlunit 73 changes the first image capture region. According to thisconfiguration, the first image capture region, which the user is payingattention to, as well as the second image capture region, which the userhas difficulty in visually recognizing, are changed in accordance withthe speed at which the image is enlarged or shrunk by the magnificationchange unit 71. Thus, even when the charge accumulation conditions orreading conditions of the first and second image capture regions arechanged, a feeling of strangeness is not given to the user. It is alsopossible to cause the user to pay higher attention to the first image.

In the first embodiment, in response to the magnification change unit 71or 72 changing the display magnification, the image capture control unit73 changes the charge accumulation conditions or reading conditions.According to this configuration, it is possible to prevent theresolution of the image from varying (or significantly varying) while orbetween before and after changing the display magnification of theimage. Thus, it is possible to prevent a feeling of strangeness frombeing given to the user while or between before and after changing thedisplay magnification of the image.

Second Embodiment

In the first embodiment, the system control unit 70 sets a centralregion 200 in accordance with the speed of the magnification change orsets a region 220 to be enlarged selected by the user, regardless ofwhat the subject is. In a second embodiment, on the other hand, a regionincluding a main subject or a region including feature points of themain subject is set.

FIG. 15 is a flowchart showing an image capture process according to thesecond embodiment. In the process shown in FIG. 15, first, an imagecapture control unit 73 starts image capture (step S1). The imagecapture control unit 73 then outputs an instruction signal to a subjectdetection unit 32 so that the subject detection unit 32 estimates a mainsubject (step S31). The subject detection unit 32 receives theinstruction signal from the image capture control unit 73 and detects(estimates) a human face serving as a main subject on the basis of imagedata generated by an image generation unit 31 using a known facedetection function. The subject detection unit 32 then outputs a signalindicating the position and size of the detected human face to a systemcontrol unit 70.

The image capture control unit 73 also outputs an instruction signal toa feature point detection unit 33 so that the feature point detectionunit 33 estimates feature points of the main subject (step S32). Thefeature point detection unit 33 receives the instruction signal from theimage capture control unit 73 and detects (estimates) eyes serving asfeature points of the main subject on the basis of image data generatedby the image generation unit 31 using a known feature point detectionfunction. The feature point detection unit 33 then outputs a signalindicating the positions and sizes of the detected human eyes to thesystem control unit 70.

Then, the system control unit 70 determines whether the user hasoperated an optical zoom switch (step S2). If the system control unit 70determines that the user has operated the optical zoom switch, a firstmagnification change unit 71 and the image capture control unit 73perform control corresponding to an optical zoom (step S3A).

FIG. 16 is a flowchart showing the control corresponding to the opticalzoom shown in FIG. 15 (step S3A). FIG. 17 is a diagram showing a mainsubject region and a feature point region set in the image captureregion when performing the optical zoom. An example display shown inFIG. 17(A) shows the state before performing the optical zoom; anexample display shown in FIG. 17(B) shows the state after performing theoptical zoom.

In the process shown in FIG. 16, the first magnification change unit 71performs the optical zoom on the basis of the operation of the opticalzoom switch by the user (step S40). Specifically, the firstmagnification change unit 71 outputs, to a lens drive controller 15, acontrol signal corresponding to the operation amount of the optical zoomswitch. Then, as shown in FIG. 17(A), the image capture control unit 73selects a region [a main subject region 230 shown in FIG. 17(A)]including a face image C3 serving as a main subject and regions [featurepoint regions 241 and 242 shown in FIG. 17(A)] including eye images f31and f32 serving as feature points of the main subject in units of blocks(step S41).

Specifically, the image capture control unit 73 selects the main subjectregion 230 including the face image C3 in units of blocks on the basisof a signal indicating the position and size of the face image C3 fromthe subject detection unit 32. The image capture control unit 73 alsoselects the feature point regions 241 and 242 including the eye imagesf31 and f32 serving as feature points in units of blocks on the basis ofa signal indicating the positions and sizes of the eye images f31 andf32 from the feature point detection unit 33. Note that the main subjectand feature points are not necessarily located in the central partincluding the optical axis O. However, while the optical zoom isperformed, a main subject and feature points are typically located inthe central part including the optical axis O.

As shown in FIG. 17(B), the human face image C3 is enlarged by theoptical zoom. Since the size of the face image C3 is increased, the sizeof a main subject region 231 including the face image C3 is alsoincreased. While the main subject region 230 shown in FIG. 17(A) is aregion consisting of 7 vertical blocks×8 horizontal blocks, the mainsubject region 231 shown in FIG. 17(B) is a region consisting of 13vertical blocks×14 horizontal blocks. As seen above, the size of themain subject region is changed by the optical zoom. Accordingly, in stepS41, the image capture control unit 73 selects any main subject regioncorresponding to the magnification change made using the optical zoom.

As shown in FIG. 17(B), the eye images f31 and f32 are also enlarged bythe optical zoom. Since the sizes of the eye images f31 and f32 areincreased, the sizes of main subject regions 243 and 244 including theeye images f31 and f32 are also increased. While the main subject region241 and 242 shown in FIG. 17(A) are each a region consisting of 2vertical blocks×2 horizontal blocks, the main subject regions 243 and244 shown in FIG. 17(B) are each a region consisting of 3 verticalblocks×3 horizontal blocks. As seen above, the sizes of the featurepoint regions are changed by the optical zoom. Accordingly, in step S41,the image capture control unit 73 selects any feature point regionscorresponding to the magnification change made using the optical zoom.

While, in FIG. 17, the main subject region is a rectangular regionincluding the main subject, it may be a circular region centered on theoptical O as shown in FIG. 12. Even when the main subject region is sucha circular region, it has to include the main subject. While the featurepoint region is a rectangular region including the feature points, itmay be a circular region centered on the optical axis O as shown in FIG.12. Even when the feature point region is such a circular region, it hasto include the feature points.

Then, the image capture control unit 73 outputs an instruction signal tothe drive unit 21 so that the drive unit 21 reads pixel signals atthinning-out rates suitable for the respective regions (main subjectregion, feature point region, other region) (step S42). Specifically,the image capture control unit 73 sets the lowest thinning-out rate forthe feature point region; sets a higher thinning-out rate than that ofthe feature point region for the main subject region; and sets a higherthinning-out rate than that of the main subject region for the regionother than the main subject region. The background image or the likeother than the main subject image is estimated to be an image that theuser is not paying attention to. For this reason, even when the image isblurred when enlarged or shrunk using the optical zoom, the user wouldnot worry about the blurred image. Accordingly, the image capturecontrol unit 73 increases the thinning-out rate of the region other thanthe main subject region to reduce the resolution of the image in thatregion.

On the other hand, the human eye images serving as feature points areestimated to be images that the user is paying highest attention to. Forexample, in portrait imaging, the user often matches the focal positionwith human eyes and wants to check whether the eyes are photogenic. Forthis reason, the image capture control unit 73 minimizes thethinning-out rate of the feature point region to maximize the resolutionof the image in that region. The image of the human face serving as amain subject is estimated to be an image that the user is payingattention to. However, areas of a human, such as the skin, have lowcontrast and therefore do not require high resolution when imagesthereof are captured. For this reason, the image capture control unit 73sets, for the main subject region, a thinning-out rate lower than thatof the region other than the main subject region and higher than that ofthe feature point region.

When the magnification is changed fast, the image moves fast andtherefore high resolution is not required. For this reason, the imagecapture control unit 73 may be configured to increase the thinning-outrates of the respective regions as the magnification is changed faster.In this case, the image capture control unit 73 may change thethinning-out rates of the regions to different degrees in accordancewith the speed of the magnification change.

In step S42, the image capture control unit 73 may cause the drive unit21 to sum up pixel signals with summation row numbers or summationcolumn numbers suitable for the respective regions rather than to readpixel signals at thinning-out rates suitable for the regions. In stepS42, the image capture control unit 73 may also cause the drive unit 21to sum up pixel signals at frame rates suitable for the respectiveregions rather than to read pixel signals at thinning-out rates suitablefor the regions.

Referring back to FIG. 15, if the system control unit 70 determines thatthe user has not operated the optical zoom switch (NO in step S2), itdetermines whether the user has operated the electronic zoom switch(step S4). If the system control unit 70 determines that the user hasoperated the electronic zoom switch, the second magnification changeunit and image capture control unit 73 perform control corresponding tothe electronic zoom (step S5A).

FIG. 18 is a flowchart showing the control corresponding to theelectronic zoom shown in FIG. 15 (step S5A). FIG. 19 includes diagramsshowing a main subject region and a feature point region set in theimage capture region when performing the electronic zoom. In the processshown in FIG. 18, the second magnification change unit 72 selects, inthe pixel region (image capture region) 113A, a region [a main subjectregion 250 shown in FIG. 19(A)] including an face image C3 serving as amain subject and regions [feature point regions 261 and 262 shown inFIG. 19(A)] including eye images f31 and f32 serving as feature pointsof the main subject in units of blocks. The second magnification changeunit 72 also selects a region 270 to be enlarged including the mainsubject region 250 and feature point regions 261 and 262 (step S51). Thesecond magnification change unit 72 then outputs, to the imageprocessing unit 30, a signal instructing the image processing unit 30 tocut out the selected region 270 to be enlarged.

As seen above, the second magnification change unit 72 selects theregion 270 to be enlarged including the main subject region 250 andfeature point regions 261 and 262 as shown in FIG. 19(A) beforeperforming the electronic zoom. That is, in the second embodiment,instead of the user, the second magnification change unit 72automatically selects the main subject region in accordance with themain subject. In the example shown in FIG. 19(A), the main subjectregion 250 is a region consisting of 7 vertical blocks×8 horizontalblocks; the feature point regions 261 and 262 are each a regionconsisting of 2 vertical blocks×2 horizontal blocks; and the region 270to be enlarged is a region consisting of 10 vertical blocks×14horizontal blocks. Even when the image is enlarged using the electroniczoom as shown in FIG. 19(B), the sizes of the main subject region 250,the feature point regions 261 and 262, and the region to be enlarged arenot changed. That is, the number of blocks included in each region isnot changed.

Then, the image capture control unit 73 causes the drive unit 21 to readpixel signals from the respective regions in the region 270 to beenlarged selected in step S51 at thinning-out rates corresponding to theenlargement ratio of the electronic zoom (step S52). For example, theimage capture control unit 73 sets, for the region 270 to be enlarged, athinning-out rate such that the resolution of the image does not varybetween before and after enlarging the image using the electronic zoom;sets, for the main subject region 250 in the region 270 to be enlarged,a lower thinning-out rate than that of the region other than the mainsubject region 250 in the region 270 to be enlarged; and sets, for thefeature point regions 261 and 262, a higher thinning-out rate than thatof the region other than the feature point regions 261 and 262 in themain subject region 250.

In step S52, the image capture control unit 73 calculates an enlargementratio on the basis of the ratio between the area of the region 270 to beenlarged and the area of the entire surface of the display panel 51. Theimage capture control unit 73 then calculates thinning-out rates afterperforming the electronic zoom on the basis of the calculatedenlargement ratio and the thinning-out rate before performing theelectronic zoom. The image capture control unit 73 then outputs, to thedrive unit 21, an instruction signal indicating the thinning-out ratesof the respective regions after performing the electronic zoom. Thedrive unit 21 reads pixel signals from the respective regions in theregion 270 to be enlarged at the thinning-out rates indicated by theimage capture control unit 73.

Then, the image capture control unit 73 makes a setting such that pixelsignals are not read from the region other than the region 270 to beenlarged in the pixel region 113A (step S53). This is because the imagein the region other than the region 270 to be enlarged in the pixelregion 113A is not displayed on the display panel 51 after performingthe electronic zoom [see FIG. 19(B)] and therefore there is no need toread pixel signals from that region.

In step S52, the image capture control unit 73 may cause the drive unit21 to sum up pixel signals with summation numbers (summation row numbersor summation column numbers) corresponding to the enlargement ratiorather than to read pixel signals at the thinning-out ratescorresponding to the enlargement ratio.

Referring back to FIG. 15, if the system control unit 70 determines thatthe user has not operated the electronic zoom switch (NO in step S4),the image capture control unit 73 performs normal reading control (stepS6). Steps S6 to S9 shown in FIG. 15 are similar to steps S6 to S9 shownin FIG. 10 and therefore the same reference signs are given and repeateddescription will be omitted.

As described above, a digital camera 1 according to the secondembodiment includes the first detection unit 32, which detects a subjecton the basis of an image captured by the image capture unit 20, and theimage capture control unit sets a region (main subject region 230)including the subject detected by the first detection unit 32, as thefirst image capture region. According to this configuration, it ispossible to keep high the resolution of the subject image that the useris paying attention to.

In the second embodiment, the digital camera 1 includes the seconddetection unit 33, which detects feature points on the basis of an imagein a particular region, and the image capture control unit 73 changesthe charge accumulation conditions or reading conditions of a thirdimage capture region (e.g., feature point region) including the featurepoints and the region other than the third image capture region in theparticular region. According to this configuration, it is possible toincrease the resolution of images of the feature points, which the useris paying highest attention to.

Third Embodiment

In the first and second embodiments, when performing the electroniczoom, the image capture control unit 73 makes a setting such thatsignals are not read from the region other than the region to beenlarged, and the display control unit 74 displays the image of theregion to be enlarged over the entire surface of the display panel 51 inan enlarged manner. In a third embodiment, on the other hand, an imagecapture control unit 73 reads signals even in the region other than theregion to be enlarged. Further, in the third embodiment, a displaycontrol unit 74 displays the image of the region to be enlarged over theentire surface of a display panel 51 in an enlarged manner, as well asdisplays an image captured in an entire pixel region 113A, in apredetermined region on the entire surface of the display panel 51.

FIG. 20 is a flowchart showing control corresponding to an electroniczoom according to the third embodiment. The control corresponding to theelectronic zoom shown in FIG. 20 is performed in step S5A in FIG. 15.The image capture control unit 73 determines whether, after performingthe electronic zoom, the user has performed an operation requesting thedisplay of the image of the region to be enlarged, as well as requestingthe simultaneous display of an image captured in the entire pixel region113A (hereafter referred to as the “entire display operation”) (stepS61).

A second magnification change unit 72 selects a main subject region,feature point regions, and a region to be enlarged in the pixel region(image capture region) 113A in units of blocks (step S62). Step S61 issimilar to step S51. The image capture control unit 73 causes a driveunit 21 to read pixel signals in the pixel region 113A atregion-specific thinning-out rates corresponding to the enlargementratio of the electronic zoom (step S63). For example, the image capturecontrol unit 73 sets, for the region to be enlarged, a thinning-out ratesuch that the resolution of the image does not vary between before andafter enlarging the image using the electronic zoom; sets, for the mainsubject region in the region to be enlarged, a lower thinning-out ratethan that of the region other than the main subject region in the regionto be enlarged; sets, for the feature point regions, a higherthinning-out rate than that of the region other than the feature pointregion in the main subject region; and sets, for the region other thanthe region to be enlarged in the pixel region 113A, a higherthinning-out rate than that of the region to be enlarged. As seen above,in the third embodiment, pixel signals are read even in the region otherthan the region to be enlarged in the pixel region 113A. Note that thehighest thinning-out rate is set for the region other than the region tobe enlarged, since the user is not paying attention to that region.

If the image capture control unit 73 determines in step S61 that theuser has not performed the entire display operation, the secondmagnification change unit 72 or image capture control unit 73 performssteps (steps S64 to S66 in FIG. 20) similar to steps S51 to S53 in FIG.18.

FIG. 21 is a diagram showing an example display when the electronic zoomis performed in the third embodiment. In step S7 in FIG. 15, the displaycontrol unit 74 displays an image shown in FIG. 21 on the display panel51. As shown in FIG. 21, a face image C4 [specifically, the image in theregion 270 to be enlarged shown in FIG. 19(A)] serving as a main subjectis displayed on the display panel 51 in an enlarged manner. A sub-screen51A having a small region is disposed on a lower-right part of thedisplay panel 51. An image captured in the entire pixel region 113A (animage of a human upper body) is displayed on the sub-screen 51A. Also,frames 600 surrounding the face images C4 are displayed on the displaypanel 51 and sub-screen 51A so that the user recognizes the position ofeach face image C4.

As described above, in the third embodiment, the image capture controlunit 73 causes the drive unit 21 to read pixel signals in the entirepixel region 113A (see step S63). Thus, the display control unit 74 candisplay the image captured in the entire pixel region 113A, on thesub-screen 51A. Since the image displayed on the sub-screen 51A issmall, a high thinning-out rate is set for the region other than theregion to be enlarged.

FIG. 22 is a diagram showing another example display when the electroniczoom is performed in the third embodiment. In the example shown in FIG.22, eye images f31 and f32 [specifically, the images in the featurepoint regions 261 and 262 shown in FIG. 19(A)] serving as feature pointsare displayed on the display panel 51 in an enlarged manner. Thesub-screen 51A having a small region is disposed on the lower-right partof the display panel 51. The image of the region 270 to be enlarged isdisplayed on the sub-screen 51A. Also, a frame 600 surrounding the faceimage C4 is displayed on the sub-screen 51A so that the user recognizesthe position of the face image C4.

As seen above, in the third embodiment, in response to the useroperating the electronic zoom switch, the display control unit 74 candisplay the image in an enlarged manner using the electronic zoom in twostages (as shown in FIGS. 21 and 22).

As seen above, a digital camera 1 according to the third embodimentincludes the display control unit 74, which simultaneously displays botha first image whose display magnification has been increased using theelectronic zoom by the second magnification change unit 72 and awide-region image (an image displayed on the sub-screen 51A) includingthe first image. According to this configuration, the user can check thewide-region image even after performing the electronic zoom. Further, inthe third embodiment, the wide-region image is an entire image beingcaptured by the image capture unit. Thus, the user can check the entireimage even after performing the electronic zoom.

Fourth Embodiment

A fourth embodiment provides a configuration in which the digital camera1 according to the first embodiment is divided into an image capturedevice 1A and an electronic apparatus 1B.

FIG. 23 is a block diagram showing the configuration of the imagingcapture device and electronic apparatus according to the fourthembodiment. In the configuration shown in FIG. 23, the image capturedevice 1A captures images of subjects. The image capture device 1Aincludes a lens unit 10, an image capture unit 20, an image processingunit 30, a work memory 40, an operation unit 55, a storage unit 60, anda first system control unit 75. The image capture unit 20, imageprocessing unit 30, work memory 40, operation unit 55, and storage unit60 of the image capture device 1A are similar to those shown in FIG. 6.Accordingly, the same elements are given the same reference signs andwill not be described repeatedly.

The electronic apparatus 1B displays images (still images, movingimages, live view images). The electronic apparatus 1B includes adisplay unit 50 and a second system control unit (control unit) 70B. Thedisplay unit 50 of the electronic apparatus 1B has a configurationsimilar to that shown in FIG. 6. Accordingly, the same elements aregiven the same reference signs and will not be described repeatedly.

The first system control unit 75 includes a first communication unit75A. The second system control unit 76 includes a second communicationunit 76B. The first communication unit 75A and second communication unit76B transmit and receive signals to and from each other by wire orwirelessly.

The elements shown in FIG. 7 (first magnification change unit 71, secondmagnification change unit 72, image capture control unit 73, and displaycontrol unit 74) may be disposed in any of the first system control unit75 and second system control unit 76. Specifically, all the elementsshown in FIG. 7 may be disposed in one of the first system control unit75 and second system control unit 76, or some of the elements shown inFIG. 7 may be disposed in the first system control unit 75, and theother elements may be disposed in the second system control unit 76.

Examples of the image capture device 1A include digital cameras,smartphones, mobile phones, and personal computers which each have imagecapture and communication functions. Examples of the electronicapparatus 1B include smartphones, mobile phones, portable personalcomputers, and portable tablets which each have a communicationfunction.

The first system control unit 75 shown in FIG. 23 is implemented when aCPU (not shown) performs processing on the basis of a control program.The second system control unit 76 shown in FIG. 23 is implemented when aCPU (not shown) performs processing on the basis of a control program.

In the configuration shown in FIG. 23, the image processing unit 30 andfirst system control unit 75 may be integral with each other. In thiscase, the functions of the image processing unit 30 and first systemcontrol unit 75 are implemented when a system control unit including oneor more CPUs performs processing on the basis of a control program.

While the present invention has been described using the embodiments,the technical scope of the invention is not limited to the scopedescribed in the embodiments. Various changes or modifications can bemade to the embodiments without departing from the spirit and scope ofthe invention. One or more of the conditions described in theembodiments may be omitted. Any forms resulting from such changes,modifications, or omission fall within the technical scope of theinvention. Elements of the embodiments or modifications thereof may becombined as appropriate and used.

While, in the above embodiments, the drive unit 21 is configured tocontrol the drive of the pixels in the pixel region 113A and to thin outpixel signals at a predetermined thinning-out rate, other configurationsmay be employed. For example, the drive unit 21 may be configured not tocontrol the drive of a predetermined proportion (a proportioncorresponding to the thinning-out rate) of the pixels in the pixelregion 113A and to control the drive of the other pixels. Even accordingto this configuration, there are produced effects similar to those whenthinning out pixel signals at the predetermined thinning-out rate. Thesignal processing chip 111 or the like may be configured to discardpixel signals read from the pixels in the pixel region 113A. Evenaccording to this configuration, there are produced effects similar tothose when thinning out pixel signals at the predetermined thinning-outrate.

While, in the first embodiment, the first magnification change unit 71changes the central region 200 in accordance with the speed of themagnification change, it may be configured not to change a centralregion having a predetermined size. The first magnification change unit71 may also be configured to set a central region in accordance with aselection made by the user.

While, in the first embodiment, the second magnification change unit 72sets a region 220 to be enlarged in accordance with a selection made bythe user, a region corresponding to a main subject or feature pointsdetected by the subject detection unit 32 may be automatically set as aregion to be enlarged, as described in the second embodiment. While, inthe second embodiment, the second magnification change unit 72automatically sets a region corresponding to a main subject or featurepoints, as a region to be enlarged, a region to be enlarged may be setin accordance with a selection made by the user, as described in thefirst embodiment.

While, in the above embodiments, the digital camera 1 is used as anexample of the electronic apparatus, the electronic apparatus is notlimited to the digital camera 1. For example, the electronic apparatusmay be any type of electronic apparatus having an image capturefunction, including smartphones, mobile phones, and personal computers.The display unit 50 of the digital camera 1 according to the firstembodiment shown in FIG. 6 may be disposed outside the digital camera.In this case, the system control unit 70 and display unit 50 are eachprovided with a communication unit that receives and transmits signals(image data, control signals, etc.) by wire or wirelessly. The imageprocessing unit 30 and system control unit 70 may be integral with eachother. In this case, the respective functions of the image processingunit 30 and system control unit 70 are implemented when a system controlunit including a single CPU performs processing on the basis of acontrol program.

While the color filters 102 form a Bayer array in the embodiments, theymay form other types of arrays. Each unit group 131 only has to includeat least one pixel. Each block also only has to include at least onepixel. Accordingly, it is also possible to capture images on imagecapture conditions which vary among the pixels.

In the above embodiments, some or all elements of the drive unit 21 maybe included in the image capture chip 113 or signal processing chip 111.Some elements of the image processing unit 30 may be included in theimage capture chip 113 or signal processing chip 111. Some or allelements of the system control unit 70 may be included in the imagecapture chip 113 or signal processing chip 111.

While, in the first embodiment, the charge accumulation conditions orreading conditions of the respective regions are changed, image captureconditions (e.g., control parameters of the image processing unit 30)other than the charge accumulation conditions or reading conditions ofthe regions may be changed in accordance with the image capturesituation.

In the above embodiments, the optical zoom and electronic zoom may beperformed simultaneously. Even in this case, it is possible to performregion-specific reading control during the optical zoom andregion-specific reading control during the electronic zoom as describedabove.

While, in the above embodiments, the thinning-out rate or the like ischanged so that the resolution of the image (image quality) does notvary between before and after performing the electronic zoom, theresolution of the image after performing the electronic zoom may beincreased or reduced compared to that before performing the electroniczoom. While, in the above embodiments, pixel signals are read even inthe peripheral region when performing the optical zoom, pixel signalsneed not be read in the peripheral region.

DESCRIPTION OF REFERENCE SIGNS

1, 1B . . . digital camera, 1A . . . image capture apparatus, 20 . . .image capture unit, 30, 30A . . . image processing unit, 31 . . . imagegeneration unit, 32 . . . subject detection unit (first detection unit),33 . . . feature point detection unit (second detection unit), 50 . . .display unit, 51 . . . display panel (display screen), 52 . . .touchscreen (selection unit), 70 . . . system control unit, 70A . . .first system control unit, 70B . . . second system control unit, 71 . .. first magnification change unit (magnification change unit), 72 . . .second magnification change unit (magnification change unit), 73 . . .image capture control unit, 74 . . . display control unit, 100 . . .image sensor

The invention claimed is:
 1. An electronic apparatus comprising: animage capture unit having a first region in which first image datashowing a first image is generated and a second region in which secondimage data showing a second image is generated; a display having a firstdisplay region in which the first image is displayed and a seconddisplay region in which the second image is displayed; a magnificationchange unit that changes display magnifications of the first and secondimages respectively displayed on the display; and an image capturecontroller that when the display magnifications are changed by themagnification change unit, performs charge accumulation control orreading control of the first and second regions in accordance withchanges in the display magnifications of the first and second imagesmade by the magnification change unit, wherein the image capturecontroller performs the charge accumulation control or the readingcontrol differently for the first region compared to the second regionbased on the display magnifications set for the first and second imagesrespectively.
 2. The electronic apparatus of claim 1, wherein the imagecapture controller controls at least one of frame rates, pixelthinning-out rates, and pixel summation numbers as the chargeaccumulation control or the reading control.
 3. The electronic apparatusof claim 2, wherein the image capture controller performs at least oneof (i) reduction of the frame rates, (ii) an increase in the pixelthinning-out rates, and (iii) an increase in the pixel summation numbersof the second region relative to the first region.
 4. The electronicapparatus of claim 1, wherein the magnification change unit includes anoptical zoom that changes a display magnification of an image by movingan image capture optical system.
 5. The electronic apparatus of claim 4,wherein the first region includes an optical axis of the image captureoptical system.
 6. The electronic apparatus of claim 1, wherein themagnification change unit includes an electronic zoom that cuts out andenlarges a part of a captured image.
 7. The electronic apparatus ofclaim 6, wherein when the magnification change unit changes the displaymagnification of the first image using the electronic zoom, the imagecapture controller performs control such that images are not captured inthe second region.
 8. The electronic apparatus of claim 6, furthercomprising a display controller that simultaneously displays both (i)the first image in which a display magnification has been increased bythe magnification change unit using the electronic zoom and (ii) awide-region image including the first image.
 9. The electronic apparatusof claim 8, wherein the wide-region image is an entire image beingcaptured by the image capture unit.
 10. The electronic apparatus ofclaim 1, wherein in response to a change to a display magnification madeby the magnification change unit, the image capture controller changes asize of the first region.
 11. The electronic apparatus of claim 1,wherein in response to a change to a display magnification made by themagnification change unit, the image capture controller changes chargeaccumulation conditions or reading conditions.
 12. The electronicapparatus of claim 1, further comprising a first detector configured todetect a subject based on an image captured by the image capture unit,wherein the image capture controller sets as the first region a regionincluding the subject detected by the first detector.
 13. The electronicapparatus of claim 12, further comprising a second detector configuredto detect a feature point based on the first image or the second image,wherein the image capture controller performs, in the first image or thesecond image, the charge accumulation control or the reading control of(i) a third region that includes the feature point and (ii) a regionother than the third region.
 14. The electronic apparatus of claim 1,wherein the display displays the second image peripheral to the firstimage.
 15. A method for controlling an electronic apparatus, the methodcomprising: setting in an image capture unit a first region in whichfirst image data showing a first image is generated and a second regionin which second image data showing a second image is generated;controlling display magnifications of the first and second imagesrespectively displayed on first and second display regions of a display;and performing charge accumulation control or reading control of thefirst and second regions in accordance with changes in the displaymagnifications when the display magnifications of the first and secondimages are changed, wherein the step of performing the chargeaccumulation control or the reading control performs the chargeaccumulation control or the reading control differently for the firstregion compared to the second region based on the display magnificationsset for the first and second images respectively.
 16. A non-transitorycomputer-readable storage medium storing a control program for causing acontroller of an electronic apparatus to perform steps of: setting in animage capture unit a first region in which first image data showing afirst image is generated and a second region in which second image datashowing a second image is generated; controlling display magnificationsof the first and second images respectively displayed on first andsecond display regions of a display; and performing accumulation controlor reading control of the first and second regions in accordance withchanges in the display magnifications when the display magnifications ofthe first and second images are changed, wherein the step of performingthe charge accumulation control or the reading control performs thecharge accumulation control or the reading control differently for thefirst region compared to the second region based on the displaymagnifications set for the first and second images respectively.